单选题 The aim of voyages Maury encouraged in the 1840s was ______.

A、 to make some sound experiments in the oceans
B、 to collect samples of sea plants and animals
C、 to estimate the length of cable that was to be made
D、 to measure the depths of two oceans

【正确答案】 D

【答案解析】细节辨认题。根据第四段中“In the 1840s，Maury had been responsible for encouraging voyages during which soundings were taken to investigate the depths of the North Atlantic and Pacific Oceans"可得出正确答案为D。